Fuse plug or the like



March 1,1932; E. J. BURNS 1,847,469

FUSE PLUG OR THE LIKE Origj 'nal Filed Nov. 25, 1927 rllllllllllllll [aw/1R0 J Bl/KMS Patented Mar. 1 I932 f UNITED STATES PATEN owl-cs;

EDWARD .1. BURNS, 011mm. nmni msacnusmrs, 'Assmxo'n 'ru smite a. comma,

- or Bos'rom massacnusnrrs I rm PLUG- OR THE LIKE Applinflnn ma inmmammrsem m beam. Ren w da uary 23.1981.

My invention. relates to. a fuseplugior electric circuits which precludes the possibility of a person inserting acoin or tin foll into the socketin order to close the circuit in 5 the eventthat the fuse is blown. Further-b more it is designed to prevent the use of afuse of larger amperage than. is proper to the oncuit, thereby reducing the fire "hazard.

Very often when a fuse blows and another one is not easily obtainable, a makeshift con,-

nection, such as tin foil or a coin, is inserted into the socketto close the, circuit. Such an expedient, although serviceable for the time being, really defeats the purpose: of the fuse )5 p111 where the circuit closer isof higher fus ibihty than the wire in the system since the wire will melt. The melting of a wire in the circuit, such as one passi'n inclosecontact to Wood, would give rise to re.

made in several sizes,fthat is to say that' the fusible element is varied to fuse at idifierent amperages. Theconventionalfuses are about five in number and range from thirty tov ten 25 amperes. It will be seenthat in the event a ten. ampere fuse should be blown and atwent five ampere substituted therefor, that the c1r-.

cuit would lose its safety factor inasmuch as.

the substituted fuse, would have ajfusibility 30 above the. danger point. By the useof my proposed fuse plug, where the same is made. upin forms-peculiar to each amperage, it will; be impossible to. interchange a. fuseplug. oi higher amperage for one of lower amperage and conversely. As will be appreciated, by making the portion of the fuse plug which remains permanently within the socket of different tapers and the recesses of the fuse carrying elements of different tapers, each taper corresponding to a certain amperage, that it will be hardly possible to substitute a fuse carrying element of one amperage for that of another. 7

ft is an object ofmy invention to. provide;

The fuse plugs now found, on the market are.

a fuse plug which is simple in structure and reliabl nfo eration-v 1 Another o ject of my inventionis to pro-. vide a, fuse plu which is 001 proof and recludes the possibility of forming a makes ift c'onnectionin the socket after the fuse has blown or the use of a. fuse of larger amperage.

' Still another object of my invention is to provide a two part fuse plug wherein one of the complementary parts remains permanently attached within the plug socket, the other or removable part containing the fuse elements; the component parts beingmade in varying ampera e sizes, each having a differenttaper so t at the fuse carrying menibers cannot be interchanged,

Other objects and advantages of my invention will be apparent from the detail'descrips tion'which follows.

Iattain. these objects and advantages by means'of the device illustrated in the accordpanying drawings wherein Figure 1 is a side elevational View of m fuse lug showing lthetwo parts associate toeter.'

' igure 2 is a plan view ofthe fuse plug showing the conventional window.

Figure 3 is a cross sectional view taken through Figure 1 showing the mode of con: tact between the component parts.

Figure 4is a perspective view ofthe male member whichis permanently attached within the'socket. l i

Figure 5 is an end view showing a conven tional fuse block fixture having a socket thereinzxfor holding the fuse plugs, in one socket the entire unit being installed. 1

Figure 6 a cross sectional 'view taken. through line B,B of Figure 5 showing the male member in place. 35,

Similar numerals refer to similar parts 4 throughout-theseveral views,

Referring to Figures 1 and 2 of the draw ings, the fuseplugfconsists efthe complemen; ta'ry membe f i a d 2.- The upper or female member 1 consists of the porcelain body 3 having the recess l which is adapted to receive the conical portion of the male member 2. A threaded ferrule 5 is spun around the porce lain body 3 whereby the upper member may be threaded into an electric socket. The porcelain body 3 is provided with a hollow 14 at its top part for a purpose to be described hereinafter.

A split rivet 6 passes through the bridge portion 7 of the porcelain body 3 and a fusible element 8 is secured to the split end of the rivet and passes at an angle through a duct in the porcelain body to the shell 5 and is soldered thereto.

The body portion 3 is provided with a flange 9 at its outermost part and a cap 10 is secured to this flange, the cap being fixed in place by spinning its lower edges around the flange. A window of mica or other transparent material is first interposed between the cap 10 and the flange 9 before the cap 10 is secured in place. It will be seen from Figure 2 that a large portion of the fusible ele' ment 8 is clearly visible through the window 11. In accordance with the usual practice, the portion of the fusible element which is visible through said window is provided with a thinned cross-section so that a break in the fuse may be detected. The head 12 of the split rivet which is on the under side of the bridge portion 7 serves as a contact point which will be mentioned in greater detail in connection with the description of the male member 2.

The. shell 5 and the cap 10 may be made of sheet brass or any other similar material, as this does not form a part of the invention. Likewise the fusible element may be of any suitable material and those now inuse are equally applicable to this fuse plug.

The male member 2 comprises a substantially conical member having its upper portion truncated and is preferably made of porcelain or some similar non-conducting material. A rivet member 15 passes through the axis of this member, both ends of the male member 2 being countersunk as snown in the drawings to form the recesses 16 and 18. The upper end or apex of the conical member is countersunk to form the recess 16. By reason of this countersunk portion it will be appreciated that the possibility of making a contact with the shell by the use of a coin or similar makeshift is practically obviated. The head of the rivet 17 which lodges in the recess 16 may be half-headed to permit only clockwise rotation. The lower recess 18 is provided with the metallic cap 19 and is of sufficient area to house the center contact of the socket. The lower end of the rivet member 15 is provided with a rivet head 20 which causes the cap member to be held tightly to the unit so that the entire body of the male member may turn with the unit when the male member is being first inserted in the socket.

The male member is provided with a flanged base 21 having the fins or spring clips 22 pro jecting from the periphery thereof and so dis posed that they turn with the male member in a right-hand direction during the insertion of the same into the socket, but upon reverse rotation grip the socket and prevent the withdrawal of the male member. In view of the fact that the head 17 is half-headed to allow only clockwise rotation, it cannot be used to turn the male member against the resistance of the fins 22. I

Referring to Figures 5 and 6 the fuse plug is shown installed in the usual fuse block provided therefor, the male member 2 being shown fixed in place, the lower recess 18 inclosing the center contact 25 of the electric socket, the ferrule of the upper portion fitting within the shell 26 of the socket.

The manner of use of the above described fuse plug is as follows. The lower or male member is first inserted in place by forcing it into the socket giving it a turning movement by turning the screw head 17 until the bottom of the male member is flush with the bottom of the socket. The fins allow the member to turn in a right-hand direction but in the event of reverse rotation they grip the sides ofthe shell and prevent the withdrawal of this member. The conical member remains at all times fixed within the socket and should never be removed. The n per or female member 1 containing the fusi le element is the only replaceable part of the fuse plug unit and is screwed in place until it hugs the conical portion of the lower member and contact is made. In the event that the fusible element is blown the entire upper part is removed and a new one substituted.

As previously stat-ed the male and female members may be made up in different sizes with different tapers, each taper being peculiar to the size of the fuse. This may be done by varying the depth of the male mem ber or changing its contour, the female fuse carrying member having a recess to conform to the male member. In this way it will be impossible to take a fuse carrying element of a higher amperage and insert it into a soclcct containing a male member which corresponds to a lower fuse amperage and the converse is equally true. It should be noted that the male member is permanently a'flixed within the socket and being of a particular shape that only the fuse carrying member having the recess to conform thereto may be used as otherwise the electrical connection with the center contact of the socket will not I lli makeshift, the fire hazard from the fusing ofelectrical wiring from excess current is eliminated. I a a I All that hasbeen said above in'the description of my preferred embodiment is oiferedby way of illustration and not limitation; I do not wish to be limited to the exact structure of the preferred embodiment shown and described, or to any particular material used in the construction of parts, or to the design of parts, but desire protection as against any variations in structure which utilize the principle of my invention and fall within the purview of my invention and are within the spirit and scope of the following claims. 7 I

The invention having been set forth, what is claimedas new and useful is 1.In combination with asocket, a fuse plug-comprising a female fuse carrying element, said fuse carrying element having a tapered recess therein, a contact point in said recess, said female fuse carrying element being provided with a conductive means, a fusible element joining said contact point and said conductive means, a male member having a base substantially equal in area to that of the socket and tapering upwardly and engaged with the tapering walls of said recess, said male member being adapted to fit within'said'recess, means on said male member to secure it against removal from said socket, and a conductor in said male member for electrically eonnecting the contact in said recess and the center contact of said socket, t

2. In combination with a fuse plug socket, a'tapered male member affixed therein, said male member having a flange portion on its base and having aligned recesses in its base and apex, a conductor passing through said male member having its extremities in said recesses, said base recess being of such size as to house the center contact of said socket, a female fuse carrying member having a ta peredrecess corresponding to the taper of said male member, the sloping side walls of said tapered male member and recess being in-engagement, a contact point within said tapered recess adapted tolengage the upper extremity of said conductor, said female fuse carrying element being provided with a conductive means, and a fusible element passing from said point to said conductive means.

3. In combination with a fuse plug socket, a fuse plug comprising in combination atapered member, locking means on said tapered member to prevent its withdrawal from said socket, aconductor contacting the center contact of said socket and extending to the top of said tapered member, a fuse carrying member, comprisinga body having a recess on one end thereof to accommodate said tapered memb'erand having the side wall of said recess engaged with the sidewall of said tapered member, a threaded rem-1e thereand having a tapered projection that is seated on the inclined side wall-of a taperedrecess in said female member, and means on said male member for locking same against removal from said out out. y

'5. In combination with a cutout, a fuse plug comprising afuse carrying member, said fuse carrying member having a tapered recess therein, a base member of insulating material being provided within said cut out, said base member being complementary to said fuse car'- rying member, said base member having a protuberant portion taperinag upwardly, said protuberant portion being a apted to fit Within and to seat on the sloping wall ofsai'd recess, and a conductor in said base member for electrically connecting the fuse carrying member to the center contact of said out out. 6. In combination with a cut out, a fuse plug comprising a fuse carrying member, said 7 fuse carrying member having a substantially conical recess therein, a base member of 'in sulating material being provided within said cutout, said base member beingcomplementa ry to said fuse carryingmember, said base member having a substantially conical portion, said conical portion being adapted to fit within and to seat on the sloping wall. of said'recess, and a conductor in saidba'se member for electrically connecting the fuse carrying member to the center contactof said cut out.

'7. In combination with a cut out, a fuse plug comprisinga fuse carrying member, said fuse carrying member having a tapered recess therein, a base member of insulating material being provided within said cut out, said base member being complementary to said fuse car'- rying member, said base member having a protuberant portion tapering upwardly, said protuberant portion being adapted to fit with;

in and to seat on the sloping wall of said 're cess, and a conductor in said base member for electrically connecting the fuse carrying member to the center contact of said out out.

8. In combination with a socket having an annular contact and a center cont-act, an insulating member located withinjsaid annular contact and upstanding abovesaid center contact, a fuse-carrying plug engaged directly with saidannular contact above said insulatingmember and surrounding-and laterally engaging said insulating member, and conducting means which passes through said insulating member and engages said center contact.

9. The combination defined in claim 8 wherein said conducting means is carried by said insulating member and said plug has a contact that engages said conducting means.

10. The combination of a socket having an annular contact, and an insulating member which is located in the bottom of the socket and upstands therein within said annular contact and has a center contact at the top, and a fuse-carrying plug surrounding and laterally engaged with said insulating member having means engaging said annular contact and a contact which engages said center contact.

11. The combination of a socket having an annular contact, a center contact, and a conical insulating member which is located within said annular contact over said center contact, and a fuse-carrying member engaged with said annular contact and having a recess in which said conical insulating member is seated, and means connecting said fusecarrying member with said center contact.

12. The combination with a socket having an annular contact and a center contact, of a fuse plug comprising a fuse-carrying member and a. separate insulating member having a circular base which is of materially lesser diameter than said annular contact and is located therein above said center contact and has a conical part which upstands above said base, and said fuse-carrying member having means engaged with said annular contact and a recess in which said conical part is laterally engaged and seated, and means which passes through said insulating mem ber and engages said center contact.

13. The combination recited in claim 12 wherein means are provided for restraining said insulating member within said annular contact.

14. A fuse plug having an annular contact and a center contact and comprising a female fuse-carrying member which carries the annular contact and has a conical recess in an end thereof, and complementary to said female member, an insulating male member at one end of which the center contact is exposed, said male member having a projection which is located in and is laterally engaged by the wall of the recess in said female member.

15. A fuse plug as defined in claim 14: wherein said male and female members have inter-engaging conical projections and recesses.

16. A fuse plug as defined in claim 1 f combined with means which restrains said male member from removal from a receptacle for said plug. 7

17. A fuse plug having an annular screwthreaded contact and a center contact and comprising a female member having a fusi ble element one end of which is connected with said annular contact, and a male insulating member at least partly located in a recess of said female member and laterally engaged by the wall of said recess and having the center contact exposed at the exposed end of said male member, and conducting means connecting the center contact with the other end of said fusible element.

18. In combination with a socket, a fuse plug comprising a female fuse-carrying element having a tapered recess therein, a male member adapted to lit within said socket and having an upwardly tapering portion adapted to seat on the tapered wall of said recess, and conducting means which connects wit-h the fuse of said fuse-carrying element adapted to pass through said male member and engage with the center contact of said socket.

19. A fuse plug having an upper fuse-carrying member and av complemental lower member, the upper member having a recessed lower end, the lower member having an upper projecting portion which occupies said recess and is laterally engaged by the wall of said recess, and conducting means which is adapted to be connected with the fuse of said fuse-carrying member and which passes through said lower member and its projecting portion.

20. A socket-type fuse plug comprising an upper fuse-carrying member having an outer screw-threaded shell adapted to be screwed into the socket and a complemental lower member adapted to be located in the bottom of the socket, the upper member having a conical recess in its lower end and said lower member having a conical projection which is seated in said recess and against the inclined wall thereof when the plug is in the socket, and conducting means which connects the fuse with the center contact of the socket and which passes through said projection and recess.

21. A socket-type fuse plug comprising an pper fuse-carrying member and a complemental lower member, said upper member having an axially located and extended recess in the lower end and said lower member having a complemental projection which is seated upon the inclined wall of said recess, and conducting means which passed through said recess and projection and has connection with the fuse.

2' A socket-type fuse having an upper fuse-carrying member having a conical recess in the bottom end thereof, and a lower member that is adapted to lie in the bottom of the socket over the center contact and has an upstanding conical insulating projection that is located within the recess and is seated on and centered by the sloping wall of said conical recess of said upper member.

23. A socket-type fuse having an upper fuse-carrying member and a lower member that is adapted tolie in the bottom of the, socket over the center contact and has an 6 upstanding conical insulating projection that.

is located within and is laterally engaged and centered by the bottom end of said upper member, and a contact at the bottom thereof that is adapted to engage the center contact 10 of the socket. V

Signed at Fall River, in the county of Bristol, State of Massachusetts, this twentysecond day of November, 1927.

EDWARD 'J. BURNS. I 

